MTN SA is ****ming me of my airtime for no reason

I’ve had this problem with MTN for months now and my problem has not been resolved…Every-time I load my airtime, part of it goes missing. I do not have subscriptions or anything that could possibly explain why my airtime disappears. I’ve logged several calls and was told they can’t see what could possibly be using up my airtime. The agents I’ve spoken to have seen no subscriptions or anything that could be using up my airtime either and yet my case remains unresolved. I’ve been asked to block all and future subscriptions as well as block my airtime from getting used up whenever my data runs out however none of these have helped. The last agent promised to escalate my case so we can get to the bottom of this but I have not been contacted ever since. I was promised I’d receive a call between 30-45 minutes from a team leader but it’s been days ever since. Not to mention that the agent I spoke to before Andisiwe was very rude and dismissive. I’m very disappointed with the service I’ve been receiving from MTN and now I’m afraid to load airtime as frequently as I’d like to cause whenever I do load it I have to add an extra amount for a subscription that doesn’t exist.